Two and a Half Men, 9 p.m. on CBS -- SEASON PREMIERE! -- Charlie runs into an ex-girlfriend (Rena Sofer) whose son bears a striking resemblance to him.

Heroes, 9 p.m. on NBC -- SEASON PREMIERE! -- Nathan's shooter is revealed. Elsewhere, Sylar visits Claire; Hiro and Ando guard a dangerous family secret and fret over the bleak future involving a dubious woman, and Suresh makes an important breakthrough.

Worst Week, 9:30 p.m. on CBS -- DEBUT! -- disaster-prone Sam Briggs and his girlfriend, Melanie, visit her parents -- who don't like Sam -- to tell them that they are engaged and expecting a child.

Boston Legal, 10 p.m. on ABC -- SEASON PREMIERE! -- Alan answers a call for help from Bethany Horowitz in a suit against a tobacco giant, but he suffers a crisis of confidence when the opposing counsel (Ally Walker) turns out to be an old girlfriend. Meanwhile, Denny is plagued by a case of performance anxiety.

House, 8 p.m. on Fox -- NEW! -- When people who received organs from a donor who was killed in an industrial accident five years earlier die suddenly, House must figure out why to save a recipient who's still alive. To track down information about the donor and the dead recipients, House hires a PI named Lucas (Michael Weston). But House also uses Lucas to snoop on Wilson as well as a colleague House is considering to replace Wilson as his friend.

Opportunity Knocks, 8 p.m. on ABC -- DEBUT! -- A family is asked trivia questions based on their knowledge of each other, with the chance to win cash and prizes. First up: The Gutierrez family from Torrance, Calif. Hosted by J.D. Roth.

90210, 8 p.m. on The CW -- NEW! -- Annie and Ty grow closer as the spring play approaches, but her parents fear things are moving too quickly. Meanwhile, Silver is overwhelmed by her stage-manager duties and leans on Dixon for help; and Naomi tries to reunite her estranged parents.

The Mentalist, 9 p.m. on CBS -- DEBUT! -- The murders of a pro golfer's wife and her doctor are investigated in the opener of a series about a former fake psychic (Simon Baker) who now uses his gift for observing details to assist a California crime unit.

Fringe, 9 p.m. on Fox -- NEW! -- During the investigation of the bizarre deaths of a bus full of commuters, Olivia, Peter and Dr. Bishop reach out to a troubled man with prognosticative powers of Pattern-related catastrophes who might be able to help them prevent another tragedy.

Dancing with the Stars, 9 p.m. on ABC -- NEW! -- One couple gets eliminated, and the 12 remaining couples perform their second routine.

Without a Trace, 10 p.m. on CBS -- SEASON PREMIERE! -- The team searches for a man whose daughter vanished years earlier. Meanwhile, Jack adjusts to a new boss (Steven Weber).

Law & Order: SVU, 10 p.m. on NBC -- SEASON PREMIERE! -- A 7-year-old boy makes accusations against his foster parents involving abusive medical testing. This leads Benson to an unsolved rape that shares something in common with this new case. New ADA Kim Greylek (Michaela McManus) helps Benson with the investigation.

The Shield, 10 p.m. on FX -- NEW! -- Following a fire at the Armenian safe house that killed two of his lieutenants, Rezian asks Vic to set up a meeting with the Mexicans, who think (thanks to Vic) that the Armenians have Pezuela's blackmail box. Meanwhile, an angry Cassidy goes to Danny with questions about her father; and Dutch questions a teenager who shot an intruder, who turns out to be the youth's classmate.

WEDNESDAY, 9/24New Adventures of Old Christine, 8 p.m. on CBS -- SEASON PREMIERE! -- Christine proposes to Barb to keep her from being deported to the Bahamas. Meanwhile, Richard considers asking new Christine to marry him.

Knight Rider, 8 p.m. on NBC -- DEBUT! -- Mike (Justin Bruening) and KITT gear up to deliver a package -- but their parcel turns out to be a man with top-secret codes inscribed in his DNA. Mike's travels turn perilous upon the encroachment of enemies, including an enigmatic lady (Paula Garces) who has detailed knowledge of a past Mike can't remember. Val Kilmer provides the voice of KITT.

Dancing with the Stars, 8 p.m. on ABC -- NEW! -- The second couple in one week is eliminated.

Gary Unmarried, 8:30 p.m. on CBS -- DEBUT! -- Painting contractor Gary (Jay Mohr) and his ex-wife (Paula Marshall) navigate kids and new relationships in this comedy, which opens with Allison announcing she is remarrying and Gary getting involved with a client who isn't convinced that he's ready to start dating again.

David Blaine: Dive of Death, 9 p.m. on ABC -- SPECIAL! -- For three days and nights, David Blaine attempts to hang upside down (and walk) on a wire five stories in the air with no safety net, using electromagnetic boots. At the show's conclusion, he plans to exit from his perch in dramatic fashion.

CSI: NY, 10 p.m. on CBS -- SEASON PREMIERE! -- The fifth season begins with Mac being taken hostage by a bank robber and then waking up in a submerged car with no memory of how he got there. The investigation seeks to unravel the truth behind the bizarre heist and the mysterious man at its center.

Lipstick Jungle, 10 p.m. on NBC -- SEASON PREMIERE! -- Nico considers telling Charles about her affair in the second-season premiere. Meanwhile, Wendy's mother (Mary Tyler Moore) visits the family just as Wendy decides to spend more time at home; and Victory hires a publicist (Rosie Perez) and dodges Joe's attempts to win her back.

THURSDAY, 9/25Survivor: Gabon -- Earth's Last Eden, 8 p.m. on CBS -- SEASON PREMIERE! -- The 17th season begins with 18 castaways marooned in Gabon, Africa, and divided into two tribes. The first person is voted out at tribal council. Jeff Probst is the host.

My Name is Earl, 8 p.m. on NBC -- SEASON PREMIERE! -- Earl revisits one of his past victims (Seth Green), a once-dying child who has grown up to be an aspiring filmmaker. Earl helps him produce a low-budget action movie, with none other than Randy earning all-around plaudits for his acting skills.

Ugly Betty, 8 p.m. on ABC -- SEASON PREMIERE! -- Betty is finally ready to make a life-altering decision after fielding proposals from Gio and Henry. Meanwhile, Ignacio gets a new job at a fast-food restaurant, and Daniel deals with the fallout of Wilhelmina's power play. Lindsay Lohan guest stars as Kimberly, Betty's high-school nemesis. Regis Philbin and Kelly Ripa appear as themselves.

My Name is Earl, 8:30 p.m. on NBC -- NEW! -- Earl and Randy set out to make peace with their childhood neighbors, but the good-hearted task only brings to the surface marital strife between their own parents (Beau Bridges and Nancy Lenehan). Elsewhere, Joy doesn't see eye-to-eye with Willy: She dupes him out of his glass eye.

The Office, 9 p.m. on NBC -- SEASON PREMIERE! -- The Dunder Mifflin staffers participate in a weight-loss program, only to become overly consumed with shedding pounds. Elsewhere, Michael works on building a friendship (and more?) with the new HR worker (Amy Ryan). And Pam attends art school in New York, leaving behind a pining Jim.

Grey's Anatomy, 9 p.m. on ABC -- SEASON PREMIERE! -- Meredith and Derek discover the morning-after side of their renewed relationship; a military doctor (Kevin McKidd) who arrives at the hospital with a trauma patient catches Cristina's eye; and the chief learns that Seattle Grace's national rankings have slipped.

ER, 10 p.m. on NBC -- SEASON PREMIERE! -- The 15th and final season opens with the staff dealing with the aftermath of the ambulance explosion. Morris and Neela have trouble handling Pratt's injuries, while Abby makes a mistake diagnosing a mother and daughter injured in the blast.

FRIDAY, 9/26America's Toughest Jobs, 8 p.m. on NBC -- NEW! -- The contestants prepare for a bullfighting job by allowing a bull to push them around in a barrel. The fighters are then graded on the level of protection they provide the riders.

Flip That House, 8 p.m. on TLC -- NEW! -- A married couple have two months and an $80,000 budget to flip a home they bought in their neighborhood for $280,000, but miscommunications with their contractors complicate their plan.

MADtv, 11 p.m. on Fox -- NEW! -- Matt Braunger plays John Mayer in parodies of his songs, including "The Jennifer Love Hewitt Song" and "Wading Through a World of Strange." Sketches include "Albania's Got Talent" and Fox News segments on Barack Obama.

SUNDAY, 9/28Extreme Makeover: Home Edition, 7 p.m. on ABC -- SEASON PREMIERE! -- A woman who took in her deceased sister's children and now heads a family of 15 receives a home makeover from Ty and his team.

Amazing Race 13, 8 p.m. on CBS -- SEASON PREMIERE! -- The race begins with 11 teams departing the Los Angeles Memorial Coliseum and flying to Salvador, Brazil, where they must either climb up a large stone staircase on their hands and knees or climb down a 240-foot cargo net. The first pit stop is Forte São Marcelo and the last team to arrive is eliminated.

The Simpsons, 8 p.m. on Fox -- SEASON PREMIERE! -- Homer and Marge get unlikely new jobs, Homer as a bounty hunter and Marge as a baker at an erotic bakery.

Family Guy, 9 p.m. on Fox -- SEASON PREMIERE! -- Brian falls in love with a woman he meets in a bookstore, but Stewie urges him to take the relationship slowly, then proceeds to see that he does. This leaves an opening for the lovelorn Cleveland.

Desperate Housewives, 9 p.m. on ABC -- SEASON PREMIERE! -- It's five years later as the fifth-season opens, and Susan is trying to hide her relationship with a new man. Meanwhile, Gaby questions her maternal skills; Bree is about to publish a cookbook as her business partner, Katherine, bristles; Lynette catches her teenage twins (Charlie and Max Carver) spearheading illegal activities; and Edie returns to Wisteria Lane with a new man in tow.

Brothers & Sisters, 10 p.m. on ABC -- SEASON PREMIERE! -- The Walker children try to make contact with their long-lost sibling without Nora's knowledge. Meanwhile, Kitty and Robert proceed with their plans to adopt, Rebecca and Justin do their best to keep their relationship a secret and Kevin faces a sudden threat to his career.

Mad Men, 10 p.m. on AMC -- NEW! -- Freddy Rumsen strikes out during a pitch meeting with his team; ever-eager Pete seizes a chance to exploit an opportunity at the office; an old friend is the beneficiary of Don's loyalty; Sara Beth proves to be a welcome ally for Betty.

Entourage, 10 p.m. on HBO -- NEW! -- Ari and Vince visit studios to pitch the smoke-jumper script, while Eric has tense but separate negotiations with Amanda and the screenwriters; Drama makes a memorable appearance on "The View."